Driving mechanism for knitting tools of warp knitting machines



June 1951 K. LIEBRANDT ETAL 2,986,909

DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed Oct. 20, 1958 8 Sheets-Sheet 1 2 (NVEnn-ORS Knm LIEBR WH-l-Y sot-UM R DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed 001:. 20, 1958 8 Sheets-Sheet 2 Fig.3

INVENTORS:

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DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed Oct. 20, 1958 8 Sheets-Sheet 3 am. LIEBA Grub WILLY QC-HKQ June 6, 1961 K. LIEBRANDT ETAL 2,986,909

DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed 001;. 20, 1958 8 Sheets-Sheet 4 Fig. 5

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DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed Oct. 20, 1958 8 Sheets-Sheet 5 KRR L ueBfinNo'r 'w'un SLHR R June 6, 1961 K. LIEBRANDT ET AL 2,986,909

DRIVING MECHANISM FOR KNITTING TOOLS Filed Oct. 20, 1958 OF WARP KNITTING MACHINES 8 Sheets-Sheet 6 A I 2s I n z I? 26 Egg 20 as 7 1s 37 r' l June 6, 1961 K. LIEBRANDT ETAL DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed 001;. 20, 1958 8 Sheets-Sheet 7 Fig.8

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DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Filed Oct. 20, 1958 8 Sheets-Sheet 8 ||llllllllllllllllllllllnnllllll I lllllllll llllmunll umuudlh.

wl Ll-Y 5:. H QGDEH United States Fatent 2,986,909 DRIVING MECHANISM FOR KNITTING TOOLS OF WARP KNITTING MACHINES Karl Liebrandt and Willy Schrader, Naila-Oberklingensp'orn, Germany; said Schrader assignor to said Liebrandt Filed Oct. 20, 1958, Ser. No. 768,337 Claims priority, application Germany Oct. 29, 1957 9 Claims. (CI. 66-86) The present invention relates to high-speed warp knitting machines and more particularly to improvements in the driving means of the knitting tools of such machines.

Since the knitting tools of Warp knitting machines have to carry out certain movements which have to be coordinated in a very particular chronological sequence relative to each other, it has always been a difficult problem to design the necessary means for driving these tools. Prior to this invention, such driving means generally consisted of cam-type gears which had the disadvantage that, when operating at the high speeds required or" modern knitting machines, they were extremely noisy and subject to excessive wear on the cam surfaces. Such camtype gears have been disclosed in the cam mechanism of the Warp knitting machine of US. Patent No. 2,427,394 of September 16, 1947, to R. F. Eshleman. Consequently, the required accuracy of the gearing soon depreciated and the individual parts thereof had to be frequently replaced. There have also been warp knitting machines in which the movement of the knitting tools was derived from two eccentric rings which were rotated at diflierent speeds. However, this duplex drive also required at least some cams and was thus subject to the same difiiculties as described above when the machine was run at a high speed. In still other Warp knitting machines, the knitting tools were operated by means of a crank gear which was driven by a main drive shaft. This gear consisted of a linkage gearing with seven joints which was formed by connecting two quadruple linkages in series with each other. However, it was found that such a gearing could not produce the desired movement of the knitting tools unless a further quadruple linkage was connected thereto. If such a gearing was mounted within a housing of smallest dimensions which was filled with oil, as is usually required for attaining high speeds, it was necessary to transmit the movement of the driven parts to the point of operation of the knitting tools by means of a further quadruple linkage, thus requiring a minimum of 13 joints and ten links for the entire driving system.

It is the principal object of the present invention to provide a driving mechanism for the knitting tools of warp knitting or similar machines which overcomes the above mentioned disadvantages and requires a smaller number of links and also a smaller number of joints than previously required, and which thus requires less material as well as less energy to carry out the proper driving function, while transmitting the required movements more smoothly to the knitting tools.

The driving mechanism according to the present invention consists of a combination of two quadruple linkages operating as crank assemblies, both of which include a crank which is mounted on the main drive shaft. The two linkages then jointly act upon power-transmitting elements which actuate the knitting tools. The two quadruple linkages may both be provided with a common crank or a common eccentric ring or each of them may have its own crank or eccentric ring which is driven by the same drive shaft. The two quadruple linkages may preferably also be connected in parallel and be designed so as to have a common stationary bearing for their rocking levers. These two rocking levers of the two quadruple linkages are preferably connected by two connecting rods, and the joint .connectingthese two rods serves as the point from which the driving force is transmitted to the knitting tools, for example, by a driving rod. It is then of a particular advantage if the two quadruple linkages are provided with two rocking levers which are pivotally mounted in a stationary position above and at opposite sides of the drive shaft and are connected with each other by means vof two connecting rods in such a manner that the joint connecting these two rods which serves as the point of transmission of the driving force is disposed between the two stationary pivot points of the rocking levers.

The driving mechanism according to the invention permits the necessary driving movements of all the knitting tools of the machine, that is, of the presser bar, the sinker, the carrying guide, and also of the eye needle, to be carried out by means of a single drive shaft. The movements of the knitting tools which are attainable by the present invention by means of a very small number of links and joints are almost identical with those attainable by means of cams, and the number of freely suspended components of the driving mechanism has been reduced to a minimum so as to attain the most favorable dynamic conditions.

The present invention is particularly concerned with a novel drive mechanism for operating various knitting tools well known in the prior art and illustrated, for example, in the patent to Zwingenberger 2,686,409. The present application particularly relates to the driving of the needle tools of the warp knitting machine and it is generally assumed that spring bearded needles are used on such a machine. The present invention is an improvement over the prior art constructions in the provision of a novel drive mechanism insteadof the cam driving mechanism as shown in the patent to Zwingenberger.

Further objects, features, and advantages of the present invention will appear from the following detailed description thereof which is to be read with reference to the accompanying drawings, in Which FIGURE 1 illustrates the movement of the needle bar in the form of curves;

FIGURE 2 shows the combination of two quadruple linkages having a common driving crank;

FIGURE 3 shows two quadruple linkages connected in parallel and having a common bearing for both rocking levers;

FIGURE 4 shows two quadruple linkages connected by means of connecting rods and having the driving'member for actuating the knitting tool connected to the member linking the two connecting rods;

FIGURE 5 shows a linkage sysem similar to that shown in FIGURE 4 with the driving member for actuating the knitting tool directly connected to one of the rocking levers;

FIGURE 6 shows the details of construction of a crank drive similar to that as illustrated in FIGURE 4;

FIGURE 7 shows a side view, partly in cross section, of FIGURE 6;

FIGURE 8 shows the details of construction of a needle driving mechanism similar to that as illustrated in FIGURE 2; while FIGURE 9 shows a side view, partly in cross section, of FIGURE 8.

Referring to the drawings, FIGURE 1 illustrates the path of movement of the needle bar and needle by means of three curves. Curve a shows the path of the needle in response to the angle of rotation of the main drive shaft which is indicated, as an abscissa. If this curve is resolved into two individual curves b and c, a sinusoidal or approximately sinusoidal movement according to the stroke curve b and a superimposed curve c will be attained which may be called a control curve. These two curves b and c, when combined due to the action of the connecting rods and rocking levers as shown in F1"- URE 2, will produce the needle movement.

FIGURE 2 shows diagrammatically a general view of the driving mechanism according to the invention for operating the needle bar and needle in accordance with the desired movement thereof. The gear housing 13 which is filled with oil has a drive shaft 14 rotatably mounted therein. A crank 15 is rigidly but adjnstably secured at one end to drive shaft 14 and terminates at its other end in a crankpin 16 on which one end of a connecting rod 17 is rotatably mounted, while the other end thereof is pivotally connected by a pivot 18 or other suitable articulated joint to a rocking lever 19 which is pivotably mounted in a stationary position at 20 in housing 13.

Aside from connecting rod 17, crankpin 16 also carries a connecting rod 21 which, in turn, is connected by an articulated joint 22 to one arm 23 of a rocking lever which is pivotably mounted in a stationary position at 24. The other arm 25 of the rocking lever is connected by a joint 26 to a connecting rod 27 which, in turn, is connected by a joint 28 and a connecting rod 29 to joint 18 on rocking lever 19 and connecting rod 17.

It will thus be evident that there are two quadruple linkages, namely, 14, 16, 18, 20 and 14, 16, 22, and 24, respectively, both of which are connected to the same crank and operate as crank drives. The driving force of this linkage mechanism is transmitted from joint 28, which links the two connecting rods 27 and 29 by means of a driving rod 30 and a joint 31 to a rocking lever 32 which is pivotably mounted at 33 in a fixed position on the machine frame and carries at its other end the needle bar 34. The difierent stages of movement of the various links and joints are indicated by points 1 to 12 on crank 15 and the corresponding points on the rocking levers and connecting rods, and particularly on joints 26 and 28 which produce the stroke curve b and the control curve c which together result in the needle curve a. It can thus be clearly seen how the revolving movement of crank 15 is transformed into the desired up-and-down movement of the needle bar 34 by means of the two combined quadruple linkages.

FIGURE 3 shows another embodiment of the invention in which two quadruple linkages are connected in parallel and have a common bearing for the two rocking levers. This driving mechanism again comprises a quadruple linkage which consists of a crank 15, a connecting rod 17, and a rocking lever 19, and it forms a crank dn've similar to that in FIGURE 2. Drive shaft 14 has further secured thereto a second crank 35, the crankpin 36 of which is pivotably connected to an arm 37 which, in turn, is pivotably connected by a joint 26 to a second rocking lever 38 which is mounted on the same stationary bearing 20 as rocking lever 19. The two quadruple linkages 14, 16, 18, 20 and 14, 36, 26, 20 are therefore disposed in a parallel relation to each other and they are connected to each other by connecting rods 27 and 29. The driving force of this mechanism is transmitted from a joint 28 between the two connecting rods 27 and 29 and by means of driving rod 30, similarly as in Figure 2. The various points of movement of crank 15 result in the movement of joint 28 as indicated by the control curve plotted adjacent thereto which, transformed by the pivotal movement of arm 32, results in the desired movement of needle bar 34 as indicated by the needle curve a.

FIGURE 4 illustrates a driving mechanism which is basically similar to that shown in FIGURE 3. It also consists of two quadruple linkages 14,16, 18, 20 and 14, 36, 26, 39, both of which operate as crank drives and are connected to each other by connecting rods 27 and 29. The mechanism according to FIGURE 4 differs, however, from that according to FIGURE 3 by the fact that the rocking lever '38 is pivotably mounted on a separate stationary bearing 39. This arrangement when applied to actual practice results in a very advantageous mechanism which requires very little space and will be described in greater detail with reference to FIGURES 6 and 7.

FIGURE 5 illustrates a further embodiment of the invention which applies the same quadruple linkage 14, 16, 1-8, and 20 as shown in the previous embodiments and also operates as a crank drive. However, insofar as the connection and cooperation of the two quadruple linkages, as well as the driving connection to the needle bar are concerned, the embodiment according to FIGURE 5 differs from those previously described. In this case the connecting rod 29 functions in a certain sense as a rocking lever for the second quadruple linkage 14, 36, 28, 18. The driving rod 30 of this mechanism is connected to joint 26' which forms the connection between rod 27' and rocking lever 40 which is pivotably mounted on a stationary bearing 41.

As previously mentioned, FIGURES 6 and 7 show the constructive details of a driving mechanism according to FIGURE 4. FIGURE 6 also illustrates the knitting tools of the machine which essentially consist of knock-over bits or sinker plates such as the one shown at 45, a set of spring-beard needles, one of which is shown at 46 on a needle bar 34, a pair of eye needles 47 and '48 for each beard needle, and a presser bar or presser 49 for periodically closing the spring beards during the loop-forming operation. It will be understood that, as conventional in such machines, a large number of spring-beard needles 46, sinker plates 45, and eye needles 47 and 48 are arranged in respective rows which extend longitudinally of the machine, that is, perpendicularly to the plane of illustration in FIGURE 6.

The drive shaft 14 is rotatably mounted in a fixed position in the gear housing 13 and acts through an eccentric ring upon the connecting rod 17 and then through 1 the pivotal joint 18 upon the rocking lever 19, which, as

in FIGURE 4, is pivotably mounted on a stationary hearing at 20. In order to render this actual embodiment of the invention as clear as possible to permit a comparison with the diagrammatical illustration according to FIGURE 4, the various pivotal joints of the first quadruple linkage have also been shown in FIGURE 6, that is, the center of drive shaft 14, crankpin 16 which, contrary to FIGURE 4 has been shown in its lower end position, further the pivotal joint 18 and the stationary bearing 20.

The second quadruple joint is formed by the eccentric ring 43 having a center 36 which acts upon the connecting rod 37 which, in turn, is connected by the pivotal joint 26 to rocking lever 38 which is pivotably mounted on a stationary hearing at 39.

The second quadruple linkage is formed by the eccentric ring 43 having a center 36 and acting upon the connecting rod 37 which is pivotably connected by the joint 26 with rocking lever 38 which is pivotably mounted on a stationary bearing at 39. The second quadruple linkage therefore consists of the pivotal joints 14, 36, 2'6, and 39. The two joints 26 and 18 are connected with each other by the two connecting rods 27 and 29 and their intermediate joint 28 which latter also forms the pivotal driving connection of the two combined linkages to the driving rod 30 which, as also shown in FIGURE 4, actuates the needle bar 34 through the rocking lever 32. The connecting member 27 consists of an eccentric member which is mounted on the pivot pin 28, while its outer bearing surfaces which are eccentrical to pin 28 form the joint 26 on which connecting rod 37 and rocking lever 38' are pivotably mounted.

It will be evident from an inspection of FIGURES 6 and 7 that this embodiment of the invention is of great advantage since it only requires a small number of links and joints, as well as a very small space and thus a relatively small gear housing, and since it operates very smoothly and reliably, while producing the desired movement of the needle bar 34 in accordance with curve a, as shown in FIGURE 4.

FIGURES 8 and 9' finally show the details of construction of a driving mechanism designed according to the linkage system as diagrammatically illustrated in FIGURE 2, in which, however, similarly as in FIGURES 6 and 7, an eccentric ring 44 on drive shaft 14 has been substituted for the crank 15 in FIGURE 2.

Although our invention has been illustrated and described with reference to the preferred embodiment thereof, we wish to have it understood that it is in no way limited to the details of such embodiment, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed our invention, What we claim is:

1. In a warp knitting machine including knitting tools and a drive housing, the improvement comprising: a drive for said tools in said housing, including a single drive shaft, crank means connected to said drive shaft, a first rocking lever pivotally supported on said housing, a first connecting rod pivotally connecting said crank means to said first rocking lever, a second rocking lever pivotally supported at one end on said housing, and a second connecting rod pivotally connecting said crank means to said second rocking lever; a third and a fourth connecting rod pivotally connected together and pivotally connected at their other ends to said second and first rocking levers, respectively, and a driven member connected to said third and fourth connecting rods at the pivotal junction thereof and connected at its other end to at least one of said knitting tools.

2. In a warp knitting machine, the improvement as defined in claim 1, further comprising a crank arm portion integral with and disposed at an angle to said second rocking lever and movable therewith, said third and fourth connecting rods being pivotally connected at said other ends to said crank arm portion.

3. In a warp knitting machine, the improvement as defined in claim 1, wherein said first and second rocking levers are pivoted one on each side of said driving shaft, each being located above said driving shaft.

4. In a Warp knitting machine, the improvement as defined in claim 1, wherein said crank means comprises a crank secured to said drive shaft.

5. A warp knitting machine as defined in claim 1, wherein said crank means comprises an eccentric ring on said drive shaft.

6. In a warp knitting machine, the improvement as defined in claim 1, wherein said drive has a common crank mounted on the single drive shaft.

7. In a warp knitting machine, the improvement as defined in claim 1, wherein said drive has a common eccentric ring mounted on the single drive shaft.

8. In a warp knitting machine, the improvement as defined in claim 1, wherein said first and second rocking levers are arranged to oscillate about a common bearing fixed to said drive housing.

9. In a warp knitting machine, the improvement as defined in claim 1, wherein said driven member includes a third rocking lever having a needle bar at one end and pivotally mounted at its opposite end, means for pivotally supporting said third rocking lever at its opposite end outside said drive housing, and a fifth connecting rod connecting said third rocking lever intermediate the end thereof and said third and fourth connecting rods at the pivotal junction thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,292,287 Peel et a1. Aug. 4, 1942 2,451,498 Lambach Oct. 19, 1948 2,461,583 Young Feb. 15, 1949 2,562,034 Hannay July 24, 1951 2,700,285 Bellini Ian. 25, 1955 UNETED STATES PATENT OFFICE ERTIFICATE 0F CGRRECTION Patent No. 2 986,909 June 6, 1961 I Karl Liebrandt et al,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent. should read as corrected below.

Column 6, line 8 for "machine as defined in claim 1," read machine the improvement as defined in claim 1, 0

Signed and sealed this 7th day of November 1961 (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer I Commissioner of Patents USCOMM-DC- 

